A305226 Number of nX4 0..1 arrays with every element unequal to 0, 1, 2, 3 or 8 king-move adjacent elements, with upper left element zero.

8, 49, 54, 116, 253, 541, 1248, 2831, 6471, 14788, 33887, 77571, 177642, 406875, 931841, 2134242, 4888087, 11195485, 25641380, 58727691, 134506571, 308066476, 705578355, 1616017727, 3701237834, 8477110559, 19415506245, 44468203154

Offset

1,1

Comments

Column 4 of A305230.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = a(n-1) +3*a(n-2) +a(n-3) -a(n-4) -3*a(n-5) -2*a(n-6) +2*a(n-7) for n>9

Example

Some solutions for n=5
..0..1..0..0. .0..0..0..0. .0..0..1..0. .0..0..0..0. .0..0..0..0
..1..1..1..0. .1..1..1..1. .0..1..1..1. .0..0..0..0. .0..0..0..0
..1..1..1..1. .1..1..1..1. .1..1..1..0. .0..0..0..0. .0..0..0..0
..1..1..0..1. .1..1..0..1. .1..1..0..0. .0..0..0..0. .0..0..0..0
..0..1..1..1. .0..1..1..1. .1..0..0..0. .1..0..0..1. .1..1..1..1

Crossrefs

Cf. A305230.

Sequence in context: A080493 A355434 A303723 * A304771 A316514 A352179

Adjacent sequences: A305223 A305224 A305225 * A305227 A305228 A305229

Keyword

nonn

Author

R. H. Hardin, May 27 2018

Status

approved